Trigger mechanism for machine guns



Feb. 2, 1937. s. G. GREEN 2,069,244

TRIGGER MECHANISM FOR MACHINE GUNS Filed Jan. 16, 1955 Fig-1- l4 25 i 43 2 /7 /2 as "I 7 7 Samuel E-Green H E a 27 j Eli EV Attnrney Patented Feb. 2, 1937 UNITED STATES PATENT OFFIQE Samuel G. Green, Gray, Ga.

Application January 16, 1935, Serial No. 2,027

3 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The subject of this invention is a trigger mechanism for machine guns.

Machine guns mounted on aircraft and adapted to fire between the blades of the propeller are operated by means of a trigger motor attached to the exterior of the gun casing and synchronized with the motor of the aircraft. The same type of gun is also mounted on other parts of the aircraft where synchronized firing is not required and it is also employed in tanks and armored cars. In these instances the gun is manually operated either directly or through remote control.

The purpose of this invention is to provide a hand trigger mechanism which may be readily interchanged with a right or left trigger motor without altering the standard equipment of the gun or interfering with its operative parts and which utilizes the attaching means of the trigger motor.

A further object is to provide an arrangement in which the trigger is maintained in a predetermined position longitudinally of the gun and is moved transversely and held in firing position by a positive and non-yielding structure.

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein:

Fig. 1 is a View in side elevation of a machine gun equipped with the improved trigger.

Fig. 2 is a sectional view on the line 2--2 of Fig. 40 1, and showing the trigger in safe or inoperative position.

Fig. 3 is a similar view with the trigger in firing position.

Fig. 4 is a sectional view on the line 4-4 of Fig.

breech bolt 6 is reciprocally mounted. The bolt has a sear which releasably holds a firing pin (not shown) and is moved by a transversely disposed sear slide 8 which is of the type employed in connection with the trigger motors of synchronized guns.

The side plates 5 are each formed with a pair of apertures 9Hl for mounting a trigger motor but in the present instance they are employed to mount the casing l l of a hand trigger mechanism 10 by means of the conventional front cleat l2 and rear cleat I 3, the latter being associated with a bolt I 4, as is well understood in the art.

A trigger l5 disposed in an opening IS in the casing has its front end pivotally mounted on a pin I! in the front part of the casing. The rear or free end of the trigger has lugs on opposite sides, the inside lug 18 having a cam surface IS on its rear face and the outside lug 20 having a cam surface 2| on its front face. The trigger is 20 normally urged outwardly away from the gun by means of a coil spring 22 which is confined between the trigger and a web 23 of the casing II.

The outer side of the casing II is formed with a longitudinally extending grooved channel 24 25 (Figs. 4 and 9) in which a slide 25, arranged substantially parallel to the trigger, is reciprocally mounted. The inside of the slide is formed with a recess 26 adapted to receive the lug 2B of the trigger and it has a cam surface 2'! adapted to coact with the cam surface 2| of the lug 26. A groove 28 is also formed on the inside of the slide and is spaced from the recess 26 to provide a solid surface 29. This groove receives a guide lug 30 on the outer side of the trigger. The lug 38 5 forms a seat for a spring 3| which is disposed in the groove 28 and serves to normally hold the slide in forward position.

For purposes of convenient assembly, the spring 3| is seated on the lip 32 of a plate 33 which is part oi the slide, being attached thereto by a bolt 34 having a collar 35 engaging the plate. A pin 36 on the lip 32 is disposed within the spring 3| and thereby holds the front part of the plate in place.

The inner face of the plate 33 is provided with a lug 31 which is accommodated in a groove 38 in the slide and has its opposite ends riding in slots 3939 in the opposite rails forming the channel 24 of the casing ll. As clearly seen in Fig. 6 the lug 3'! serves as a stop member to limit reciprocation of the slide and plate with respect to the casing l I.

The slide is retracted by acting on the bolt 34 either directly or through a cable 30. The slide is normally held in the forward or inoperative position (Fig. 2) by the spring 3|. In this position the trigger is urged outwardly by the spring 22 to dispose the lug 20 in the recess 26 of the slide with the cam surfaces 2| and 21 in contact.

On retraction of the slide 25 the trigger is cammed inwardly towards the gun and is positively held in the firing position with the lug 20 seated on the solid surface 29 of the slide as shown in Fig. 3. When the slide is released the parts assume the positions shown in Fig. 2.

In continuous firing the trigger is held in the firing position while the breech bolt is reciprocating. On the forward stroke the bolt approaches battery with the sear slide 8 in the cooked position shown in Fig. 2 and when it is almost home the slide 8 engages the cam surface E9 of the lug l8 and is moved inwardly to release the sear.

The position of the trigger longitudinally of the gun is always the same and the sear slide 8 will always be actuated at a predetermined position in the travel of the bolt which position is just before the bolt is home. The impact of the sear slide 8 on the trigger will not vary its position and it will not be transmitted to the slide 25.

I claim:

1. In a trigger mechanism, a casing adapted to be attached to a gun and having an aperture and a channel, a trigger pivotally mounted in the casing with its free end arranged to move through the aperture therein, lugs on opposite sides of the free end of the trigger, the lug on the inside of the trigger having a cam. surface on its rear face and the lug on the outside of the trigger having a cam surface on its front face, a slide mounted in the channel of the casing substantially parallel to the trigger and having a recess with a cam surface adapted to coact with the cam surface on the outer lug of the trigger, and a spring seated on the trigger and acting on the slide to normally hold it in forward position.

2. In a trigger mechanism, a casing adapted to be attached to a gun, a trigger pivotally mounted in the casing and having a lug intermediate its ends a slide mounted in the casing substantially parallel to the trigger and having a groove for receiving the lug of the trigger, a spring confined between the lug of the trigger and the slide, and means on the slide for displacing the trigger.

3. In a trigger mechanism, a casing adapted to be attached to a gun and formed with channel members having opposite slots, a trigger-actuating slide mounted in the channel and having a recess, and a plate secured to the slide and having a lug extending across the recess in the slide and riding in the slots of the channel members of the casing.

SAMUEL G. GREEN. 

